He began his studies in Livorno, Italy, and later earned the degree of Doctor of Philosophy and Medicine at the University of Pisa in March 1808.

Antommarchi took up this position at the behest of Napoleon's mother Maria Letizia Ramolino and his uncle Cardinal Joseph Fesch.

However, Napoleon was not so impressed by Antommarchi's medical skills and even dismissed him from his service a couple of times, only to let him resume his duty soon after.

In the last moments of illness, Antommarchi was assisted by Dr Archibald Arnott, who was accepted by Napoleon at the pressing demands from his two officers, Count Montholon and Grand-Marshal Bertrand.

Numerous copies of this cast have been made and some can be seen at these locations: Antommarchi's diary contained detailed records of his medical care for Napoleon.

Antommarchi became Prosector to Mascagni who left manuscripts and drawings for an intended publication of a comprehensive complete anatomy with life-size figures.

When Antommarchi returned, he published these plates, printed from lithographs, under his own name in a monumental work which appeared from 1823 to 1826 under the title of: "Planches anatomiques du corps humain exécutées d'après les dimensions naturelles accompagnées d'un texte explicatif".

Possible motivations for this controversy, for both parties, can include but are not limited to: Despite a post-mortem cast of Bonaparte's right hand, allegedly by Antommarchi, sold[31] and exhibited in museums,[32][33] none of the persons that were present in Saint Helena when Napoleon died ever reported that such a cast occurred.